Variable-capacity compressor

Abstract

Variable displacement compressor is provided with a displacement control valve ( 2 ) that can change an opening degree of supplying passage ( 44, 46 ) between a valve seat (VS) and a valve body (VB), thereby changing the pressure in a crank chamber ( 9 ). The displacement control valve ( 2 ) is accommodated within a control valve chamber ( 5 c ) in a rear housing ( 5 ) and fixed in place by means of a circlip ( 50 ). A cutout ( 50 g ) is formed between the displacement control valve ( 2 ) and the circlip ( 50 ) and/or between the circlip ( 50 ) and the rear housing ( 5 ). A clearance (C) formed by the cutout ( 50 g ) and the like inhibits the transmission of vibrations caused by impacts between the valve seat (VS) and the valve body (VB). This makes the variable displacement compressor quiet, reduces costs by obviating the need for additional components, and results in excellent durability.

1 . A variable displacement compressor comprising:
 a housing including a suction chamber, a crank chamber, a discharge chamber, and a control valve chamber; and   a displacement control valve accommodated in the control valve chamber and fixed to the housing by a circlip, which is engaged with an engagement groove of the housing, wherein   the displacement control valve includes a valve seat and a valve body arranged in a passage connecting the discharge chamber and the crank chamber or a passage connecting the crank chamber and the suction chamber, the valve body is accommodated in a valve case, an external signal is input to a coil to change an opening degree of the passage between the valve seat and the valve body so that pressure of the crank chamber can be changed, and the coil is protected by a cover;   vibration generated by impact between the valve seat and the valve body is transmitted through a path extending from the valve seat via the valve case and the circlip to the housing, the variable displacement compressor being characterized in that   at least one of the circlip, the cover, and the engagement groove includes a cutout or a recess in the path, and a clearance defined by the cutout or the recess forms a means for suppressing transmission of the vibration.   
     
     
         2 . The variable displacement compressor according to  claim 1 , wherein
 the circlip includes a C-shaped engagement portion, which engages with the engagement groove, and a wide portion, which is formed at two ends of the engagement portion and has a fitting hole into which pliers is fitted;   the engagement portion includes the cutout formed in a widthwise direction to avoid contact with the displacement control valve; and   the vibration transmitting suppressing means is the clearance defined by the cutout.   
     
     
         3 . The variable displacement compressor according to  claim 1 , wherein
 the circlip includes an opposing surface that opposes the displacement control valve;   the displacement control valve includes an end surface that opposes the opposing surface;   the end surface includes the recess that avoids contact with the opposing surface; and   the vibration transmitting suppressing means is the clearance defined by the recess.   
     
     
         4 . The variable displacement compressor according to  claim 1 , wherein
 the circlip includes an opposing surface that opposes the displacement control valve;   the displacement control valve includes an end surface that opposes the opposing surface;   the opposing surface includes the recess that avoids contact with the end surface; and   the vibration transmitting suppressing means is the clearance defined by the recess.   
     
     
         5 . The variable displacement compressor according to  claim 1 , wherein
 the engagement groove is defined by a first engagement surface and a second engagement surface that are spaced apart by an equal distance in a circumferential direction;   the circlip includes a first surface and a second surface spaced apart by an equal distance in the circumferential direction to engage with the engagement groove;   at least one of the first surface and the second surface includes a recess for avoiding contact with the first engagement surface and the second engagement surface; and   the vibration transmitting suppressing means is the clearance defined by the recess.   
     
     
         6 . The variable displacement compressor according to  claim 1 , wherein
 the engagement groove is defined by a first engagement surface and a second engagement surface that are spaced apart by an equal distance in a circumferential direction;   the circlip includes a first surface and a second surface spaced apart by an equal distance in the circumferential direction to engage with the engagement groove;   at least one of the first engagement surface and the second engagement surface includes the recess so that the distance between the first engagement surface and the second engagement surface is greater than the thickness of the circlip to avoid contact with the first surface and the second surface; and   the vibration transmitting suppressing means is the clearance defined by the recess.   
     
     
         7 . The variable displacement compressor according to  claim 1 , wherein the vibration transmitting suppressing means is a means for attenuating vibration transmitted in at least either one of between the displacement control valve and the circlip and between the circlip and the housing. 
     
     
         8 . The variable displacement compressor according to  claim 7 , wherein the cover is sealed by an O-ring, and the vibration attenuating means is the recess formed in a circumference of the cover closer to an opening of the control valve chamber than the O-ring. 
     
     
         9 . The variable displacement compressor according to  claim 7 , wherein
 the engagement groove is defined by a first engagement surface and a second engagement surface spaced apart by an equal distance in a circumferential direction;   the circlip is elastically deformable;   the distance between the first engagement surface and the second engagement surface of the engagement groove is greater than the thickness of the circlip so that the circlip elastically deforms to obtain the clearance between the first engagement surface and the second engagement surface; and   the vibration attenuating means is the clearance.